Human experiments of metabolism, blood alkalization and oxygen effect on control and regulation of breathing. I: room air exercise test / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Under the guidance of the holistic integrative physiology medicine, we reanalyzed the data during symptom-limited maximum cardiopulmonary exercise testing (CPET) in order to investigate control and regulatory mechanism of breathing.</p><p><b>METHODS</b>This study investigated 5 normal volunteers who accepted artery catheter, performed CPET room air. Continuous measured pulmonary ventilation parameters and per minute arterial blood gas (ABG) analysis sample parameters during exercise. All CPET and ABG data changes were standard analyzed and calculated.</p><p><b>RESULTS</b>With gradually increasing power, minute oxygen uptake(every breath oxygen uptake x respiratory rate = O2 paulse x heart rate) and minute ventilation (tidal volume x respiratory rate) showed nearly linear progressive increase during the CPET(compared with the rest stage, P < 0.05 - 0.001); Minute ventilation increased even more significant after the anaerobic threshold (AT) and respiratory compensation point. PaO2 was increased at recovery 2 minutes (P < 0.05); PaCO2 was decreased after anaerobic threshold 2 minutes (P < 0.05); [H+]a was increased from AT (P < 0.05), and rapidly raised at last 2 minutes, remained high at recovery. Lactate was increased rapidly from AT (compared with resting, P < 0.05); bicarbonate decreased rapidly from AT (compared with resting, P < 0.05) and it's changed direction was contrary to lactic acid.</p><p><b>CONCLUSION</b>In order to overcome the resistance of the power during exercise, metabolic rate othe body increased, respiratory change depend upon the change metabolism, and the accumulation of acidic products exacerbated respiratory reactions at high intensity exercise.</p>

Human experiments of metabolism, blood alkalization and oxygen effect on control and regulation of breathing. II: room air exercise test after blood alkalization / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Basis on the dynamic changes of the ventilation and arterial blood gas parameters to symptom-limited maximum cardiopulmonary exercise testing (CPET), we further investigate the effect of alkalized blood by drinking 5% NaHCO3 on ventilation during exercise.</p><p><b>METHODS</b>After drinking 5% NaHCO3 75 ml (3.75 g) every 5 min, total dosage of 0.3 g/Kg, 5 volunteers repeated CPET. All CPET and ABG data changes were analyzed and calculated. At the same time, CPET and ABG parameters after alkalized blood were compared with those before alkalized blood (control) used paired t test.</p><p><b>RESULTS</b>After alkalized blood, CPET response patterns of parameters of ventilation, gas exchange and arterial blood gas were very similar (P > 0.05). All minute ventilation, tidal volume, respiratory rate, oxygen uptake and carbon dioxide elimination were gradually increased from resting stage (P < 0.05-0.001), according to the increase of power loading. During CPET after alkalized blood, ABG parameters were compared with those of control: hemoglobin concentrations were lower, CaCO2 and pHa were increased at all stages (P < 0.05). The PaCO2 increased trend was clear, however only significantly at warm-up from 42 to 45 mmHg (P < 0.05). Compared with those of control, only the minute ventilation was decreased from 13 to 11 L/min at resting (P < 0.05).</p><p><b>CONCLUSION</b>Even with higher mean CaCO2, PaCO2 and pHa, lower Hba and [H+]a, the CPET response patterns of ventilatory parameters after alkalized blood were similar.</p>

Human experiments of metabolism, blood alkalization and oxygen effect on control and regulation of breathing. III: pure oxygen exercise test after blood alkalization / 中国应用生理学杂志

<p><b>OBJECTIVE</b>After performed symptom-limited maximum cardiopulmonary exercise testing (CPET) before and after acute alkalized blood, we repeated CPET with pure oxygen.</p><p><b>METHODS</b>Five volunteers, 3hr after alkalizing blood room air CPET, re-performed CPET inhaling from Douglas bag connected with pure oxygen tank. We compared with those of room air CPETs before and after alkalized blood.</p><p><b>RESULTS</b>After alkalized blood oxygen CPET had a similar response pattern as those of CPETs before and after blood alkalization. During the CPET, all breath frequency, minute ventilation and tidal volume at each stage were similar to those of CPETs before and after alkalized blood (P > 0.05),except there was a lower peak tidal volume than those of both CPETs and a slightly higher resting minute ventilation only than CPET after alkalized blood (P > 0.05). After alkalized blood, oxygen CPET, all PaO2 and SaO2 and most Hb were lower than those of both CPETs (P < 0.05). The pHa and [HCO3-]a were higher than those of CPET before alkalized blood (P < 0.05); but were not CPET after alkalized blood (P > 0.05). PaCO2 was similar to that of CPET before alkalized blood (P > 0.05), but was lower than that of CPET after alkalized blood at resting and warm-up (P < 0.05); then was similar to both CPETs at anaerobic threshold (P > 0.05); but was higher at peak exercise higher than those of both CPETs (P < 0.01). Oxygen increased 2,3 volunteers' workload and time at AT and peak exercises.</p><p><b>CONCLUSION</b>Respiratory response pattern to oxygen CPET after alkalized blood is similar to those of both CPETs before and after alkalized blood. The CPET response is dominantly depended upon metabolic rate, but not levels of pHa, PaCO2 and PaO2.</p>